diff --git a/0-0-intro/src/main/java/com/bobocode/intro/ExerciseIntroduction.java b/0-0-intro/src/main/java/com/bobocode/intro/ExerciseIntroduction.java index 35d925636..0b758fe7d 100644 --- a/0-0-intro/src/main/java/com/bobocode/intro/ExerciseIntroduction.java +++ b/0-0-intro/src/main/java/com/bobocode/intro/ExerciseIntroduction.java @@ -1,5 +1,5 @@ package com.bobocode.intro; - +import java.util.Base64; import com.bobocode.util.ExerciseNotCompletedException; /** @@ -23,9 +23,9 @@ public class ExerciseIntroduction { * @return "The key to efficient learning is practice!" */ public String getWelcomeMessage() { - // todo: implement a method and return a message according to javadoc - throw new ExerciseNotCompletedException(); + return "The key to efficient learning is practice!"; } + /** * Method encodeMessage accepts one {@link String} parameter and returns encoded {@link String}. @@ -38,8 +38,8 @@ public String getWelcomeMessage() { * @param message input message * @return encoded message */ - public String encodeMessage(String message) { - // todo: switch to branch "completed" in order to see how it should be implemented - throw new ExerciseNotCompletedException(); - } + +public String encodeMessage(String message) { + return Base64.getEncoder().encodeToString(message.getBytes()); } +} \ No newline at end of file diff --git a/1-0-java-basics/1-3-0-hello-generics/src/main/java/com/bobocode/basics/Box.java b/1-0-java-basics/1-3-0-hello-generics/src/main/java/com/bobocode/basics/Box.java index 5a2d860ee..1613fcfc3 100644 --- a/1-0-java-basics/1-3-0-hello-generics/src/main/java/com/bobocode/basics/Box.java +++ b/1-0-java-basics/1-3-0-hello-generics/src/main/java/com/bobocode/basics/Box.java @@ -7,18 +7,18 @@ *

* todo: refactor this class so it uses generic type "T" and run {@link com.bobocode.basics.BoxTest} to verify it */ -public class Box { - private Object value; +public class Box { + private T value; - public Box(Object value) { + public Box(T value) { this.value = value; } - public Object getValue() { + public T getValue() { return value; } - public void setValue(Object value) { + public void setValue(T value) { this.value = value; } -} +} \ No newline at end of file diff --git a/1-0-java-basics/1-3-1-crazy-generics/src/main/java/com/bobocode/basics/CrazyGenerics.java b/1-0-java-basics/1-3-1-crazy-generics/src/main/java/com/bobocode/basics/CrazyGenerics.java index 751d5899f..ea0252325 100644 --- a/1-0-java-basics/1-3-1-crazy-generics/src/main/java/com/bobocode/basics/CrazyGenerics.java +++ b/1-0-java-basics/1-3-1-crazy-generics/src/main/java/com/bobocode/basics/CrazyGenerics.java @@ -1,14 +1,11 @@ package com.bobocode.basics; import com.bobocode.basics.util.BaseEntity; -import com.bobocode.util.ExerciseNotCompletedException; import lombok.Data; import java.io.Serializable; -import java.util.Collection; -import java.util.Comparator; -import java.util.List; -import java.util.Objects; +import java.util.*; +import java.util.function.Predicate; /** * {@link CrazyGenerics} is an exercise class. It consists of classes, interfaces and methods that should be updated @@ -33,8 +30,8 @@ public class CrazyGenerics { * @param – value type */ @Data - public static class Sourced { // todo: refactor class to introduce type parameter and make value generic - private Object value; + public static class Sourced { // todo: refactor class to introduce type parameter and make value generic + private T value; private String source; } @@ -45,11 +42,11 @@ public static class Sourced { // todo: refactor class to introduce type paramete * @param – actual, min and max type */ @Data - public static class Limited { + public static class Limited { // todo: refactor class to introduce type param bounded by number and make fields generic numbers - private final Object actual; - private final Object min; - private final Object max; + private final T actual; + private final T min; + private final T max; } /** @@ -59,8 +56,9 @@ public static class Limited { * @param – source object type * @param - converted result type */ - public interface Converter { // todo: introduce type parameters + public interface Converter { // todo: introduce type parameters // todo: add convert method + R convert(T param); } /** @@ -70,10 +68,10 @@ public interface Converter { // todo: introduce type parameters * * @param – value type */ - public static class MaxHolder { // todo: refactor class to make it generic - private Object max; + public static class MaxHolder> { // todo: refactor class to make it generic + private T max; - public MaxHolder(Object max) { + public MaxHolder(T max) { this.max = max; } @@ -82,11 +80,13 @@ public MaxHolder(Object max) { * * @param val a new value */ - public void put(Object val) { - throw new ExerciseNotCompletedException(); // todo: update parameter and implement the method + public void put(T val) { + if (val.compareTo(max) > 0) { + max = val; + } // todo: update parameter and implement the method } - public Object getMax() { + public T getMax() { return max; } } @@ -97,8 +97,8 @@ public Object getMax() { * * @param – the type of objects that can be processed */ - interface StrictProcessor { // todo: make it generic - void process(Object obj); + interface StrictProcessor> { // todo: make it generic + void process(T obj); } /** @@ -108,19 +108,19 @@ interface StrictProcessor { // todo: make it generic * @param – a type of the entity that should be a subclass of {@link BaseEntity} * @param – a type of any collection */ - interface CollectionRepository { // todo: update interface according to the javadoc - void save(Object entity); + interface CollectionRepository> { // todo: update interface according to the javadoc + void save(T entity); - Collection getEntityCollection(); + C getEntityCollection(); } /** * {@link ListRepository} extends {@link CollectionRepository} but specifies the underlying collection as - * {@link java.util.List}. + * {@link List}. * * @param – a type of the entity that should be a subclass of {@link BaseEntity} */ - interface ListRepository { // todo: update interface according to the javadoc + interface ListRepository extends CollectionRepository> { // todo: update interface according to the javadoc } /** @@ -133,7 +133,10 @@ interface ListRepository { // todo: update interface according to the javadoc * * @param a type of collection elements */ - interface ComparableCollection { // todo: refactor it to make generic and provide a default impl of compareTo + interface ComparableCollection extends Collection, Comparable> { // todo: refactor it to make generic and provide a default impl of compareTo + default int compareTo(Collection other) { + return Integer.compare(this.size(), other.size()); + } } /** @@ -147,7 +150,7 @@ static class CollectionUtil { * * @param list */ - public static void print(List list) { + public static void print(List list) { // todo: refactor it so the list of any type can be printed, not only integers list.forEach(element -> System.out.println(" – " + element)); } @@ -160,8 +163,13 @@ public static void print(List list) { * @param entities provided collection of entities * @return true if at least one of the elements has null id */ - public static boolean hasNewEntities(Collection entities) { - throw new ExerciseNotCompletedException(); // todo: refactor parameter and implement method + public static boolean hasNewEntities(Collection entities) { + for (BaseEntity e : entities) { + if (e.getUuid() == null) { + return true; // todo: refactor parameter and implement method + } + } + return false; // todo: refactor parameter and implement method } /** @@ -173,8 +181,10 @@ public static boolean hasNewEntities(Collection entities) { * @param validationPredicate criteria for validation * @return true if all entities fit validation criteria */ - public static boolean isValidCollection() { - throw new ExerciseNotCompletedException(); // todo: add method parameters and implement the logic + public static boolean isValidCollection(Collection entities, Predicate validationPredicate) { + return entities.stream() + .allMatch(validationPredicate); + } /** @@ -187,8 +197,10 @@ public static boolean isValidCollection() { * @param entity type * @return true if entities list contains target entity more than once */ - public static boolean hasDuplicates() { - throw new ExerciseNotCompletedException(); // todo: update method signature and implement it + public static boolean hasDuplicates(List entities, T targetEntity) { + return entities.stream() + .filter(entity -> entity.getUuid().equals(targetEntity.getUuid())) + .count() > 1; } /** @@ -202,10 +214,23 @@ public static boolean hasDuplicates() { */ // todo: create a method and implement its logic manually without using util method from JDK + public static Optional findMax(Iterable elements, Comparator comparator) { + if (elements.iterator().hasNext()) { + T max = elements.iterator().next(); + for (T e : elements) { + if (comparator.compare(e, max) > 0) { + max = e; + } + } + return Optional.of(max); + } + return Optional.empty(); + } + /** * findMostRecentlyCreatedEntity is a generic util method that accepts a collection of entities and returns the * one that is the most recently created. If collection is empty, - * it throws {@link java.util.NoSuchElementException}. + * it throws {@link NoSuchElementException}. *

* This method reuses findMax method and passes entities along with prepare comparator instance, * that is stored as constant CREATED_ON_COMPARATOR. @@ -216,6 +241,11 @@ public static boolean hasDuplicates() { */ // todo: create a method according to JavaDoc and implement it using previous method + public static T findMostRecentlyCreatedEntity(Collection entities) { + return findMax(entities, CREATED_ON_COMPARATOR).orElseThrow(); + } + + /** * An util method that allows to swap two elements of any list. It changes the list so the element with the index * i will be located on index j, and the element with index j, will be located on the index i. @@ -226,10 +256,14 @@ public static boolean hasDuplicates() { * @param j index of the other element to swap */ public static void swap(List elements, int i, int j) { - Objects.checkIndex(i, elements.size()); - Objects.checkIndex(j, elements.size()); - throw new ExerciseNotCompletedException(); // todo: complete method implementation + swapHelper(elements, i, j); + } + + private static void swapHelper(List elements, int i, int j) { + T temp = elements.get(i); + elements.set(i, elements.get(j)); + elements.set(j, temp); } } -} +} \ No newline at end of file